Fracturing Utilizing an Air/Fuel Mixture

ABSTRACT

A method of producing subterranean fractures in geologic formations for the extraction of hydrocarbons includes flowing an air and fuel mixture into a well hole. The well hole may then be sealed with a packer plug creating a compression chamber with the air and fuel mixture. A liquid, such as water, may be pumped into the well hole to create pressure in the compression chamber. The build-up of pressure eventually causes auto-ignition of the air and fuel mixture which fractures the formation. The water may then rush into the compression chamber which thermally shocks the area causing additional fractures. The water may vaporize to steam and thoroughly disinfect the well hole eliminating the need for added biocides.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/180,473, filed on Jun. 16, 2015, the entirety of which isexpressly incorporated by reference herein.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The preferred embodiments relate generally to the field of hydrocarbonrecovery from the earth, and more specifically, to fracturingunderground formations for the recovery of hydrocarbons using a methodof fracturing the formations with the use of an auto-igniting air andfuel mixture.

2. Discussion of the Related Art

Fracturing as a method to stimulate shallow, hard rock oil wells datesback to the 1860s. Dynamite or nitroglycerin detonations were used toincrease oil and natural gas production from petroleum bearingformations. On Apr. 25, 1865, Civil War veteran Col. Edward A. L.Roberts received a patent for a Torpedo with U.S. Pat. No. 47,458.Stimulation of wells with acid, instead of explosive fluids, wasintroduced in the 1930s.

The relationship between well performance and treatment pressures wasstudied as far back as 1947 where 1,000 US gallons of gelled gasoline(essentially napalm) and sand from the Arkansas River was injected intothe gas-producing limestone formation at 2,400 feet (730 m). Theexperiment was not very successful as deliverability of the well did notchange appreciably. The Halliburton company is known to have performedthe first two commercial hydraulic fracturing treatments in StephensCounty, Okla., and Archer County, Tex. Since then, hydraulic fracturinghas been used to stimulate approximately one million oil and gas wellsin various geologic regimes.

American geologists became increasingly aware that there were hugevolumes of gas-saturated sandstones with permeability too low (generallyless than 0.1 millidarcy) to recover the gas economically. Starting in1973, massive hydraulic fracturing was used in thousands of gas wells inthe San Juan Basin, Denver Basin, the Piceance Basin, the Green RiverBasin, and in other hard rock formations of the western US. Other tightsandstone wells in the US made economically viable by massive hydraulicfracturing were in the Clinton-Medina Sandstone, and Cotton ValleySandstone.

Horizontal oil or gas wells were unusual until the late 1980s. Then,operators in Texas began completing thousands of oil wells by drillinghorizontally in the Austin Chalk, and giving massive slickwaterhydraulic fracturing treatments to the wellbores. Horizontal wellsproved much more effective than vertical wells in producing oil fromtight chalk; sedimentary beds are usually nearly horizontal, sohorizontal wells have much larger contact areas with the targetformation.

Due to shale's low permeability, technological research, development anddemonstration were necessary before hydraulic fracturing was acceptedfor commercial application to shale gas deposits. In 1976, the UnitedStates government started the Eastern Gas Shales Project, a set ofdozens of public-private hydraulic fracturing demonstration projects.During the same period, the Gas Research Institute, a gas industryresearch consortium, received approval for research and funding from theFederal Energy Regulatory Commission.

In 1997, taking the slickwater fracturing technique used in East Texasby Union Pacific Resources (now part of Anadarko Petroleum Corporation),Mitchell Energy (now part of Devon Energy), applied the technique in theBarnett Shale of north Texas. This made gas extraction widely economicalin the Barnett Shale, and was later applied to other shales. The firsthorizontal well in the Barnett Shale was drilled in 1991, but was notwidely done in the Barnett until it was demonstrated that gas could beeconomically extracted from vertical wells in the Barnett.

According to the United States Environmental Protection Agency (EPA),hydraulic fracturing is a process to stimulate a natural gas, oil, orgeothermal energy well to maximize extraction. The EPA defines thebroader process as including the acquisition of source water, wellconstruction, well stimulation, and waste disposal.

A hydraulic fracture is formed by pumping fracturing fluid into awellbore at a rate sufficient to increase pressure at the target depth(determined by the location of the well casing perforations), to exceedthat of the fracture gradient (pressure gradient) of the rock formation.The fracture gradient is defined as pressure increase per unit of depthrelative to density, and is usually measured in pounds per square inch,per foot, or bars per metre. The rock formation cracks, and the fracturefluid permeates the rock extending the crack further, and further, andso on. Fractures are localized as pressure drops off with the rate offrictional loss, which is relevant to the distance from the well.Operators typically try to maintain “fracture width”, or slow itsdecline following treatment, by introducing a proppant into the injectedfluid (a material such as grains of sand, ceramic, or other particulate,thus preventing the fractures from closing when injection is stopped andpressure removed). Consideration of proppant strength and prevention ofproppant failure becomes more important at greater depths where pressureand stresses on fractures are higher. The propped fracture is permeableenough to allow the flow of gas, oil, salt water and hydraulicfracturing fluids to the well.

During the process, fracturing fluid leakoff (loss of fracturing fluidfrom the fracture channel into the surrounding permeable rock) occurs.If not controlled, it can exceed 70% of the injected volume. This mayresult in formation matrix damage, adverse formation fluid interaction,and altered fracture geometry, thereby decreasing efficiency.

The location of one or more fractures along the length of the well holeis preferably strictly controlled by various methods that create or sealholes in the side of the wellbore. Hydraulic fracturing is performed incased wellbores, and the zones to be fractured are accessed byperforating the casing at those locations.

Hydraulic-fracturing equipment used in oil and natural gas fieldsusually consists of a slurry blender, one or more high-pressure,high-volume fracturing pumps (typically powerful triplex or quintuplexpumps) and a monitoring unit. Associated equipment includes fracturingtanks, one or more units for storage and handling of proppant,high-pressure treating iron, a chemical additive unit (used toaccurately monitor chemical addition), low-pressure flexible hoses, andmany gauges and meters for flow rate, fluid density, and treatingpressure. Chemical additives are typically 0.5% percent of the totalfluid volume. Fracturing equipment operates over a range of pressuresand injection rates, and can reach up to 100 megapascals (15,000 psi)and 265 litres per second (9.4 cu ft/s) (100 barrels per minute).

The fracturing fluid varies depending on fracturing type desired, andthe conditions of specific wells being fractured, and watercharacteristics. The fluid can be gel, foam, or slickwater-based. Fluidchoices include tradeoffs: more viscous fluids, such as gels, are betterat keeping proppant in suspension; while less-viscous and lower-frictionfluids, such as slickwater, allow fluid to be pumped at higher rates, tocreate fractures farther out from the wellbore. Important materialproperties of the fluid include viscosity, pH, various rheologicalfactors, and others.

The water brought in is mixed with sand and chemicals to create frackingfluid. Approximately 40,000 gallons of chemicals are used perfracturing. A typical fracture treatment uses between 3 and 12 additivechemicals. Although there may be unconventional fracturing fluids,typical chemical additives can include one or more of the following:

-   -   Acids—hydrochloric acid or acetic acid is used in the        pre-fracturing stage for cleaning the perforations and        initiating fissure in the near-wellbore rock.    -   Sodium chloride (salt)—delays breakdown of gel polymer chains.    -   Polyacrylamide and other friction reducers decrease turbulence        in fluid flow and pipe friction, thus allowing the pumps to pump        at a higher rate without having greater pressure on the surface.    -   Ethylene glycol—prevents formation of scale deposits in the        pipe.    -   Borate salts—used for maintaining fluid viscosity during the        temperature increase.    -   Sodium and potassium carbonates—used for maintaining        effectiveness of crosslinkers.    -   Glutaraldehyde—used as disinfectant of the water (bacteria        elimination).    -   Guar gum and other water-soluble gelling agents—increases        viscosity of the fracturing fluid to deliver proppant into the        formation more efficiently.    -   Citric acid—used for corrosion prevention.    -   Isopropanol—used to winterize the chemicals to ensure it doesn't        freeze.

The most common chemical used for hydraulic fracturing in the UnitedStates in 2005-2009 was methanol, while some other most widely usedchemicals were isopropyl alcohol, 2-butoxyethanol, and ethylene glycol.

Typical fluid types are:

-   -   Conventional linear gels. These gels are cellulose derivative        (carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl        hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl        methyl cellulose), guar or its derivatives (hydroxypropyl guar,        carboxymethyl hydroxypropyl guar), mixed with other chemicals.    -   Borate-crosslinked fluids. These are guar-based fluids        cross-linked with boron ions (from aqueous borax/boric acid        solution). These gels have higher viscosity at pH 9 onwards and        are used to carry proppant. After the fracturing job, the pH is        reduced to 3-4 so that the cross-links are broken, and the gel        is less viscous and can be pumped out.    -   Organometallic-crosslinked fluids zirconium, chromium, antimony,        titanium salts are known to crosslink the guar-based gels. The        crosslinking mechanism is not reversible, so once the proppant        is pumped down along with cross-linked gel, the fracturing part        is done. The gels are broken down with appropriate breakers.    -   Aluminum phosphate-ester oil gels. Aluminum phosphate and ester        oils are slurried to form cross-linked gel. These are one of the        first known gelling systems.

For slickwater it is common to include a temporary reduction in theproppant concentration to ensure the well is not overwhelmed withproppant causing a screen-off. As the fracturing process proceeds,viscosity reducing agents such as oxidizers and enzyme breakers aresometimes then added to the fracturing fluid to deactivate the gellingagents and encourage flowback. The oxidizer reacts with the gel to breakit down, reducing the fluid's viscosity, and ensuring that no proppantis pulled from the formation. An enzyme acts as a catalyst for breakingdown the gel. Sometimes pH modifiers are used to break down thecrosslink at the end of a hydraulic fracturing job since many require apH buffer system to stay viscous. At the end of the job, the well iscommonly flushed with water (sometimes blended with a friction reducingchemical) under pressure. Injected fluid is recovered to some degree andmanaged by several methods such as underground injection control,treatment and discharge, recycling, or temporary storage in pits orcontainers. New technology is continually being developed to betterhandle waste water and improve re-usability.

There are a number of potential public health impacts of exposures tochemical and radioactive pollutants as a result of hydraulic fracturing.Some evidence suggests that contamination of groundwater, if it occurs,is most likely to be caused by leakage through the vertical borehole.Contamination of groundwater from the underground hydraulic fracturingprocess itself (i.e., the fracturing of the shale) is unlikely. However,surface spills of hydraulic fracturing fluids or wastewater may affectgroundwater, and emissions to air also have the potential to impact onhealth.

Further environmental impacts of hydraulic fracturing include airemissions for the generators and pumps necessary to produce theincredible fracturing pressures, high water consumption, watercontamination from all the chemical additives, land use, noisepollution, and health effects on humans. Moreover, overall costassociated with such known systems with expensive equipment (capitaloutlay and maintenance) and high cost of operation is dramatic, creatinga need for lower cost systems. In addition, about 8.9 acres of land isneeded per each drill pad for surface installations. Well pad andsupporting structure construction significantly fragments landscapeswhich likely has negative effects on wildlife.

What is therefore needed is a method of fracturing difficult-to-extractformations which does not use harmful chemical additives. What isfurther needed is a method of fracturing subterranean formations whileoccupying a much smaller footprint at the well's surface. An additionalneed is a method of fracturing that uses considerably less energy andtherefore is less costly and produces less harmful byproducts andemissions.

SUMMARY AND OBJECTS OF THE INVENTION

Fracturing a subterranean formation begins by drilling a well hole intothe earth. A combustible mixture of an oxidizer and a fuel, preferablyan air and fuel mixture, may be flowed into the well hole. An aqueousmixture with a mass may be pumped into the well hole which compressesthe combustible mixture with the mass of the aqueous mixture pressingdown on the combustible mixture. The combustible mixture may be causedto auto-ignite under the compressive force of the mass of the aqueousmixture thereby fracturing at least a portion of the subterranean welllocation. A plurality of hydrocarbons emitted from the fracturedsubterranean well location may then be collected.

The fuel for the air and fuel mixture may include any known fuel, butpreferably is one of a group including diesel fuel, a carbohydrateincluding wheat flour, corn flour, rice flour, barley flour, organicstarches, powdered plastics, powdered coal, powdered fecal matter. Aplurality of piezo crystals may be added to the air and fuel mixture asthey provide sparking under pressure and friction, which may assistdetonation of the air and fuel mixture when desired.

The fuel preferably is diesel fuel and the diesel fuel is aerosolizedwith the oxidizer. The oxidizer is at least one of aluminum nitrate,ammonium nitrate, and ambient air at a surface of the well hole.

A packer plug may be inserted into the well hole before and after theair and fuel mixture. The packer plug may be pressed further down thewell hole thus creating the application of pressure to auto-detonate theair and fuel mixture.

Following detonation of the air and fuel mixture, the well hole may besterilized with steam generated from the auto-detonation of the aqueousmixture eliminating the need of a bacteriacide.

Frozen water may be used as a pressure barrier between the aqueousmixture and the air and fuel mixture allowing the application ofpressure to the air and fuel mixture without submersing the air andfuel. A proppant may also be added to the aqueous mixture to ensurenewly created fissures remain open. The aqueous mixture may include amixture of liquid water and a gel made from at least one of guar andcross linked polymers.

According to a first preferred embodiment, a method of fracturingincludes drilling a well hole into a subterranean well location andflowing a combustible mixture of an oxidizer and a fuel into the wellhole. Next, the method includes flowing an aqueous mixture with a massinto the well hole, compressing the combustible mixture with the mass ofthe aqueous mixture, and causing the combustible mixture to auto-igniteunder a compressive force of the mass. As a result, at least a portionof the subterranean well location is fractured with the explosion fromthe auto-ignition such that a plurality of hydrocarbons emitted from thefractured subterranean well location can be collected.

In another preferred embodiment, a process of collecting hydrocarbonsfrom a subterranean environment includes drilling a well hole to apredetermined depth sufficient to reach a hydrocarbon deposit, andflowing an air and fuel mixture into the well hole. This method includesauto-detonating the air and fuel mixture with an application of pressureinto the well hole, so that the subterranean environment is fracturedwith the energy of the auto-detonation. A plurality of hydrocarbons inthe hydrocarbon deposit from the well hole is then recovered.

In a further aspect of this preferred embodiment, the method furtherincludes inserting a packer plug into the well hole and driving it downthe well hole, thus creating the application of pressure toauto-detonate the air and fuel mixture. An aqueous mixture is pumpedinto the well hole to create the application of pressure with a weightof the aqueous mixture.

In another aspect of this preferred embodiment, the well hole issterilized with a steam generated from the auto-detonation of theaqueous mixture and without a bacteriacide.

In yet another preferred embodiment, a method of fracturing subterraneanlocation includes forming a hole extending from a surface of the earthinto a hydrocarbon deposit, and inserting an aerosol into the well holeto a depth sufficient to reach the hydrocarbon deposit. Then, a liquidwith a mass is flowed into the hole, compressing the aerosol within thehydrocarbon deposit with a pressure from a weight of the liquid.Furthermore the aerosol is pressurized with the weight of the liquid toa pressure of sufficient magnitude causing auto-ignition of the aerosol,and fracturing the subterranean location with an explosion from theauto-ignition.

In another aspect of this preferred embodiment, a packer plug isinserted into the hole wherein the packer plug includes a pressurereducing orifice after flowing the liquid, and provides a pressure intothe well hole through the pressure reducing orifice, thus furtherfracturing the subterranean location.

In yet another aspect of this embodiment, the hole is disinfected with asteam generated from the explosion.

According to another aspect of this embodiment, the aerosol is formedwith a combustible fuel and air that is ambient surrounding the surfaceof the earth proximate the hole.

In another aspect of this preferred embodiment, a proppant is mixed withthe liquid at least one of prior and during the flowing of the liquidinto the hole. Further, the liquid is flowed into the subterraneanlocation following the explosion.

According to yet another aspect of this embodiment, the liquid flowsinto the hole following the auto-ignition and provides additionalfracturing by creating a steam and a thermal shock to the subterraneanlocation.

In a further aspect of this preferred embodiment, the liquid includes amixture of liquid water and a gel made from at least one of guar andcross linked polymers.

These, and other aspects and objects of the present invention, will bebetter appreciated and understood when considered in conjunction withthe following description and the accompanying drawings. It should beunderstood, however, that the following description, while indicatingpreferred embodiments of the present invention, is given by way ofillustration and not of limitation. Many changes and modifications maybe made within the scope of the present invention without departing fromthe spirit thereof, and the invention includes all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

A clear conception of the advantages and features constituting thepresent invention, and of the construction and operation of typicalembodiments of the present invention, will become more readily apparentby referring to the exemplary, and, therefore, non-limiting, embodimentsillustrated in the drawings accompanying and forming a part of thisspecification, wherein like reference numerals designate the sameelements in the several views, and in which:

FIG. 1 illustrates a schematic view of a first embodiment of theinvention with an open hole and single packer;

FIG. 2 illustrates a schematic view of an alternative embodiment of theinvention with two packers in a production cased well hole;

FIG. 3A illustrates a schematic perspective view of an alternativeembodiment of the invention with two packers in a production cased wellhole as shown in FIG. 2, with further clarity;

FIG. 3B is an exploded view of a portion of the fracking apparatus shownin FIG. 3A;

FIG. 4 illustrates a partial cross-section schematic side view of thepacker as used with respect to FIG. 2;

FIG. 5A illustrates a partial cross-section side view of the packer asused with respect to FIG. 3A;

FIG. 5B is a partial cross-sectioned view of the fracking apparatus ofFIG. 5A installed in a formation;

FIG. 6 illustrates a partial cross section side view of anotherembodiment of the invention;

FIG. 6A is a detail view of a portion of the fracking apparatus shown inFIG. 6; and

FIGS. 7-13 illustrate chronological schematic cross-sectional side viewsof a method of executing the fracking operation of a preferredembodiment.

In describing preferred embodiments of the invention, which areillustrated in the drawings, specific terminology will be resorted tofor the sake of clarity. However, it is not intended that the inventionbe limited to the specific terms so selected and it is to be understoodthat each specific term includes all technical equivalents, whichoperate in a similar manner to accomplish a similar purpose. Forexample, the words “connected”, “attached”, “coupled”, or terms similarthereto are often used. They are not limited to direct connection butinclude connection through other elements where such connection isrecognized as being equivalent by those skilled in the art.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, one embodiment of the invention is shown. Above theground surface 24 piping 28 connects an air compressor with a powdermixing hopper 12. The powder mixing hopper 12 may add either a powdercarbohydrate into the piping 28 or it may be configured to inject anyother fuel source such as diesel fuel. The powder carbohydrate mayinclude any carbohydrate such as corn starch, flour, animal/human waste,or any other known starch. The powder and/or fuel is injected into thepiping 28 and is effectively aerosolized by the air compressor 10. Thisforms an air fuel mixture within the piping 28.

Ambient air from above the ground surface 24 is ingested into the aircompressor 10. Pressurized air is created and clean dry air is flowed toand through an air educator located at the bottom of the hopper 12. Theair educator in the hopper 12 creates a vacuum that pulls in theexplosive powder or fuel mixture contained in the hopper 12. The air andfuel mixture then flows to and thru a check valve 22. This check valve22 prevents the mixture from flowing backwards in the piping 28.

From the check valve 12 the air and fuel mixture flows through thepiping 28 and to the bottom of the well 30. A packer, such as aninflatable packer 36, may be inserted into the well 30 and act as a stopwhich prevents the air and fuel mixture 56 from reaching a portion ofthe well 30 where fracturing is not desirable. The inflatable packer 36then creates a sealed well area 40 that does not get fractured.

The air and fuel mixture, now inside the well 30, is pumped through thewell 30 until it is stopped by the inflatable packer 36. This packer 36stops the flow of the air and fuel mixture 56 and causes it to flow intoany naturally occurring fissures 34 in the formation.

The air fuel mixture 56 flows through a “pig” launcher 18 just above theground surface 24. During the pumping of the air and fuel mixture 56,its velocity is kept low in order to allow heat built up by friction inthe air and fuel mixture 56 to be dissipated into the formation. Thistransfer of heat in to the formation prevents premature ignition of theair and fuel mixture 56.

An added check valve 20 and pressure gage 16 is used to monitor the flowand into the well head 26. The pig launcher 18 is an injection portwhere a “packer pig” may be introduced into the well head 26. A packerpig or pig refers to a plug that may be inserted down into the well 30and act as a barrier that restricts transmission of fluids, but allowsthe fluid to build up and generate pressure. Preferably, the pig is inthe form of a dissolvable and temporary product. One embodiment mayinclude ice but any substance that dissolves may be used. The ice pig 32can plug up the well 30 and allow a liquid 38 to be pumped in by theliquid pump 14. After the well 30 has received a predetermined amount ofexplosive air and fuel mixture 56, the ice pig is placed in the launcher18 and the liquid (water) pump 14 is engaged. The liquid pump 14 may beused to deliver any aqueous mixture. Preferably, water is used and allother chemicals are avoided. This prevents introduction of harmfulsurfactants, biocides, or any other chemicals. Water pumped by theliquid pump then pushes the ice pig 32 ahead of it, blocking theexplosive air and fuel mixture 56 from getting behind it, and creating awater column.

This column of water becomes a piston causing the explosive air and fuelmixture 56 to compress within the compression chamber 42. The rate ofthis compression is controlled to again allow the heat of compression tobe dissipated in to the formation and avoid premature ignition of themixture.

Once a predetermined amount of water 38 (or water and proppant) has beenpumped in to the well 30, the rate of injection is abruptly anddramatically increased. This rapid increase in water injectioncompresses the explosive air and fuel mixture 56 within the compressionchamber 42 at a rate at which the formation cannot effectively acceptthe transfer of heat. At this point, heat builds up within the explosiveair and fuel mixture 56 and auto-ignition temperature is reach causingit to detonate.

All of the kinetic energy of the explosion goes in to the formation. Anynaturally occurring methane within the naturally occurring fissures willadd to the explosion. The explosion will create a large amount of heatand it will be absorbed by the formation. The ice pig 32 at this pointmay be dissolved and the water 38 that once provided pressure on theexplosive mixture will now flow, under pressure, in to the fissures 34where they will be thermally shocked causing fracturing. Heat will betransferred into the water creating steam whose pressure will createadditional fracturing 34. The water will eventually condense, becomingdistilled water with its microbes killed by the heat, and flow out ofthe well with well gas and or oil and produced water.

Referring now to FIGS. 2, 3A, 3B, 4, 5A, and 5B, an alternativeembodiment is described. FIGS. 2, 3A, and 3B show an overall schematicof the invention while FIGS. 4 and 5A and 5B show an inventive packerfor executing the process, illustrated, e.g., schematically togetherwith the system in FIGS. 2, 3A, and 3B.

Similar with respect to FIG. 1, and with more specific reference toFIGS. 2 and 3A, ambient air above the ground surface 34 is ingested intoair compressor 10. Pressurized air is generated by the air compressor 10and clean dry air is flowed to and thru an air educator located at thebottom of hopper 12. The air educator of the hopper 12 creates a vacuumthat pulls in an explosive air and fuel mixture 56 contained in thehopper 12. The air and fuel explosive mixture 56 then flows to and thrua check valve 22. This check valve 22 prevents the air and fuel mixture56 from flowing backwards in the piping 28. From the check valve 22 theair and fuel mixture 56 flows to the output of liquid pump 14, andthrough a pig launcher 18 (see FIG. 3B), check valve 20, pressure gage16 and in to the oil well head 26.

Now inside the well 30, the air and fuel mixture 56 is pumped down thewell 30 and into the firing chamber 50 of the inflatable packer 46.FIGS. 4 and 5A show more detailed and close-up views of the inflatablepacker 46. The explosive air and fuel mixture 56 flows though thesmaller diameter stinger 44 and in to the area between the inflatablepacker 46 and the inflatable packer 36. Once inside this compressionchamber 42 the air and fuel mixture 56 will attempt to flow back throughthe filter pad 52 and into the lower pressure area behind the inflatablepacker 46 and outside of the compression chamber 42. The filter pad 52will capture the powder or other fuel in the air and “load” up. Thisloading creates a rise in the air pressure in the production tubingcasing 30 causing the inflatable packer 46 to “set”, closing off thearea between the inflatable packer 46 and the casing 30. This pressureincrease will be detected as a rise in pressure at the pressure gage 16at the ground surface 24.

As the air and fuel mixture 56 is pumped into the compression chamber42, its velocity is kept low in order to allow heat built up by frictionin the mixture to be dissipated into the casing 30. Keeping the air andfuel mixture 56 pumped at a low velocity allows ample time to transferfrictional heat into the casing 30 and prevents premature ignition ofthe air and fuel mixture 56. This also eliminates the need for addinglubricants and other fracking fluids to the air and fuel mixture 56.

Once a rise in pressure is detected at the ground surface 24 by thepressure gage 16, the compression chamber 42 between the inflatablepacker 46 and the other inflatable packer 36 is full of sufficient airand fuel mixture 56. The inflatable packer 46 is then ready. A ball ofice, or an ice pig 32, may then be inserted into the pig launcher 18 andthe liquid pump 14 is engaged.

Water pumped by the liquid pump 14 pushes the ice pig 32 ahead of it,blocking the explosive air and fuel mixture 56 from getting behind it,and creating a water column. This column of water becomes a pistoncausing the explosive air and fuel mixture 56 within the compressionchamber 42 to compress. The rate of this compression is controlled toagain allow the heat of compression to be dissipated in to the casing 30and avoid premature ignition of the air and fuel mixture 56.

Once a predetermined amount of water (or water and proppant) has beenpumped into the well, the rate of injection is abruptly and dramaticallyincreased. This rapid increase in water injection rapidly compresses theexplosive air and fuel mixture 56 in the firing chamber 50 at a rate atwhich the inflatable packer 46 cannot effectively accept the transfer ofheat. At this point, heat builds up within the explosive air and fuelmixture 56 and auto-ignition temperature is reached causing detonation.Heat and explosive gases are now directed through the stinger 44 and into the explosive laden compression chamber between the inflatablepackers 46 and 36. This causes ignition of the explosive air and fuelmixture 56 between the packers 46 and 36. Much of the pressure from theexplosion is prevented from moving back thru the packer by the reducedand smaller opening in the stinger 46, as shown best in FIG. 4 and FIGS.5A and 5B.

To maintain fracturing in the region of interest, the separation betweenthe packers (such as the mechanical or inflatable delta “P” packer andthe inflatable or settable mechanical packer, shown in FIGS. 3A and 5B)is preferably maintained. Typically, the packers are set so as tomaintain their positions in the well during the fracturing event. Thisarrangement relies on setting the packers so the friction force betweenthe outer surface of the packer and the inner wall of the well issufficient to prevent either of the packers from dislodging from itslocation and possibly shooting back through the well. However,increasing this clamping force when setting the packers can be difficult(a system which allows the user to set the packers with less clampingforce is desired), and the resultant friction force is ofteninsufficient to maintain packer position during fracturing. Therefore,as an option to aid in maintaining this separation, a link (as shown inFIGS. 3A and 5B) may be added between the packers to couple the two toone another. By coupling the two, maintaining packer position is ensuredso that the surface area of the compression chamber is constant andfracturing occurs in the region of interest.

To accommodate the turn of well 30 from the vertical to the horizontal,the link may include several bars or sections coupled, for example,using a clevis fastener and an eye (shown schematically in FIGS. 3A and5B) provided on the ends of two or more successive sections of the link.In this way, the desired distance between the packers can be maintainedthrough the fracturing process.

All of the kinetic energy of the explosion is absorbed in to theformation and spreads through any naturally occurring fissures 34. Anynaturally occurring methane within the naturally occurring fissures 34will add to the explosion. The explosion of the air and fuel mixture 56may by itself cause new fissures 34 to form. The water that onceprovided pressure on the explosive air and fuel mixture 56 will now flowunder pressure through the dissolved ice pig 32 and in to the fissures34 where they will be thermally shocked causing additional fracturing.Heat will be transferred into the water creating steam whose pressurewill create even more fracturing. The water will eventually condense,becoming distilled water with its microbes killed by the heat, and flowout of the well with wells gas and/or oil and produced water.

Referring now to FIGS. 6A and 6B, another embodiment of the invention isshown. Ceramic balls 62 may be imbedded into the well casing 30. Theembedded ceramic balls 62 provide a convenient way to create openings inthe casing for fracturing the formation that surrounds it. This casing30 is traditionally installed in the well and cemented in a normalmanner. Inflatable packers may then be positioned in the areas betweenthe groupings of embedded ceramic balls shown as packer placement 58.

When an air and fuel mixture 56 is detonated (as outlined with respectto FIGS. 1 and 2), the ceramic balls 62 are forced out of their embeddedpockets 64 and into the formation 66 creating a fracture 68 and leavingthe remains of the ceramic ball as a proppant to hold the newlyfractured 68 formation 66 open. This method eliminates the need forconventional perforations in the casing 30 and can be used in“overbalanced” (pressurized formation) as well as “balanced” and“underbalanced” (negative pressure) formations. Balanced formationsdefine formations with a consistent density and hardness of thesurrounding geology. Underbalanced refers to geology with inconsistentdensity and hardness, which makes it difficult to achieve uniformfracturing. Some formations may fracture before others absorbing all ofthe explosive energy. The ceramic balls 62 may be affixed to the casingin any known manner, but preferably are epoxied into dimple pockets 64that may be machined in to the casing 30. The ceramic balls 62 ensureeven and thorough fracturing.

FIGS. 7-13 summarize and illustrate a preferred embodiment of theprocess and the method of fracturing. Beginning with FIG. 7, a well hole72 may be drilled into the earth below the ground surface 24. In orderto keep the well hole 72 open, a steel liner, or well casing, 30 may bepressed into the well hole. Cement 70 or concrete is typically pumpedaround the casing 30 for added strengthening. The casing 30 and cement70 also ensure that the well hole 72 is sealed and any surroundingaquifer 82 is protected. Any aquifers 72 are commonly located closer tothe ground surface 24 than the targeted fracking area 84. For example,the typical fracking area is about 1.5 miles below the ground surface24. Most aquifers 82 are 100 feet or less below the ground surface 24.

As shown in FIG. 8, following creation of the well hole 72, a firstpacker plug 36 may be inserted into the well hole 72. A second packerplug 46 may then be placed into the well hole 72 creating a pressurechamber 42, as described with respect to FIGS. 1 and 2. FIG. 9 disclosesthe air and fuel mixture 56 which may be pumped into the compressionchamber 42. Air may be displaced out of the compression chamber and exitpacker plug 46 out of a vent hole. The vent hole may include a checkvalve to prevent re-entry of displaced material. As the air and fuelmixture 56 is pumped into the compression chamber 42, the pressurewithin the compression chamber 42 is monitored to ensure ignition is notprematurely attained.

Shown in FIG. 10, the ice pig 32 may then be placed into the well hole72 to create a pressure barrier and prevent any fluid from rushing tothe compression chamber 42. The fluid is also kept separate to ensureproper detonation of the air and fuel mixture 42. Referring to FIG. 11water 76 may be injected into the well hole 72. The ice pig 32 forms apressure barrier and keeps the water 76 from filling the entire wellhole 72. The ice pig 32 acts as a movable piston and compresses thespace in the well hole building up pressure 74. The pressure 74 pressesagainst the compression chamber 42.

Referring to FIG. 12, the pressure causes the air and fuel mixturewithin the compression chamber 42 to auto-ignite and explode causingfractures 68. The water 76 may then rush in to fill the well hole 72after the ice pig 32 is dissolved. The intense heat generated by theexplosion vaporizes the water 76 forming steam 80 as seen in FIG. 13.The steam 80 expands causing additional fractures 68. The heat from thesteam 80 and the explosion also sterilize the well hole 72 and eliminatethe need for chemicals commonly used to prevent bacteria growth.

The pure water may then be pumped out of the well hole 72 and anyhydrocarbons may be collected from the well. As harmful fracking fluidsare not necessary, the water may be re-used and safely stored. Thesurrounding aquifers are also further protected as there are nochemicals to leech into the ground. Any oil mixed within the water mayalso be easily skimmed and collected.

An added benefit is that the auto-ignition pressure point of the air andfuel mixture 56 is significantly lower than the amount of pressurerequired to fracture using known methods, such as hydraulic fracturing.Known fracking methods require 20,000 psi or greater pressure to crackthe formations. Producing this kind of pressure requires a great deal ofenergy. This energy is produced above the ground surface by enginescombusting hydrocarbons. Many engines are commonly used to operate amultitude pumps. The inventive fracking method only requires arelatively small amount of pressure to fracture the subterraneanformations. The weight of the water column injected into the wellproduces the majority of the pressure needed to auto-ignite the air andfuel mixture. Only about 200 psi of water pressure is required to begenerated with pumps at the ground surface 24. This reduces thefootprint of the fracking site at the ground surface and alsodrastically reduces the amount of fuel needed for the pumps. Fewer pumpsare required, less vehicles to move the pumps, less personnel to operatethe equipment, and an overall lower economic expenditure.

Additionally, while inflatable packers are disclosed throughout, otherpackers are considered acceptable for use. For example, mechanicalpackers may be used for execution of the invention. One example of amechanical packer is manufactured by World Oil Tools in Calgary,Alberta, Canada. These packers, or any other packer, may be used in thepreferred embodiments.

There are virtually innumerable uses for the present apparatus andmethods, all of which need not be detailed here. Additionally, all thedisclosed embodiments can be practiced without undue experimentation.Further, although the best mode contemplated by the inventors ofcarrying out the present invention is disclosed above, practice of thepresent invention is not limited thereto. It will be manifest thatvarious additions, modifications, and rearrangements of the features ofthe present invention may be made without deviating from the spirit andscope of the underlying inventive concept (as disclosed herein).

In addition, the individual components of the present inventiondiscussed herein need not be fabricated from the disclosed materials,but could be fabricated from virtually any suitable materials.Furthermore, all the disclosed features of each disclosed embodiment canbe combined with, or substituted for, the disclosed features of everyother disclosed embodiment except where such features are mutuallyexclusive.

It is intended that the appended claims cover all such additions,modifications, and rearrangements. Expedient embodiments of the presentinvention are differentiated by the appended claims.

What is claimed is:
 1. A method of fracturing comprising: drilling awell hole into a subterranean well location; flowing a combustiblemixture of an oxidizer and a fuel into the well hole; flowing an aqueousmixture with a mass into the well hole; compressing the combustiblemixture with the mass of the aqueous mixture; causing the combustiblemixture to auto-ignite under a compressive force of the mass; fracturingat least a portion of the subterranean well location with an explosionfrom the auto-ignition; and collecting a plurality of hydrocarbonsemitted from the fractured subterranean well location.
 2. The method ofclaim 1 wherein the fuel is one of a group including diesel fuel, acarbohydrate including wheat flour, corn flour, rice flour, barleyflour, organic starches, powdered plastics, powdered coal,and powderedfecal matter, and a plurality of piezo crystals.
 3. The method of claim2 wherein the fuel is diesel fuel and the diesel fuel is aerosolized andthe oxidizer is at least one of aluminum nitrate, ammonium nitrate, andambient air at a surface of the well hole.
 4. A process of collectinghydrocarbons from a subterranean environment comprising: drilling a wellhole to a predetermined depth sufficient to reach a hydrocarbon deposit;flowing an air and fuel mixture into the well hole; auto-detonating theair and fuel mixture with an application of pressure into the well hole;fracturing the subterranean environment with the energy of theauto-detonation; and recovering a plurality of hydrocarbons in thehydrocarbon deposit from the well hole.
 5. The method of claim 4 furthercomprising inserting a packer plug into the well hole and driving itdown the well hole thus creating the application of pressure toauto-detonate the air and fuel mixture.
 6. The method of claim 4 furthercomprising pumping an aqueous mixture into the well hole to create theapplication of pressure with a weight of the aqueous mixture.
 7. Themethod of claim 6 further comprising sterilizing the well hole with asteam generated from the auto-detonation of the aqueous mixture andwithout a bacteriacide.
 8. The method of claim 5 wherein the packer plugcomprises at least one of a frozen water formations and a dissolvingsolid inserted between the air and fuel mixture and the application ofpressure.
 9. A method of fracturing subterranean location comprising:forming a hole extending from a surface of the earth into a hydrocarbondeposit; inserting an aerosol into the well hole to a depth sufficientto reach the hydrocarbon deposit; flowing a liquid with a mass into thehole; compressing the aerosol within the hydrocarbon deposit with apressure from a weight of the liquid; pressurizing the aerosol with theweight of the liquid to a pressure of sufficient magnitude causingauto-ignition of the aerosol; and fracturing the subterranean locationwith an explosion from the auto-ignition.
 10. The method of claim 9further comprising inserting a packer plug into the hole prior toflowing the liquid.
 11. The method of claim 9 further comprising:inserting a packer plug into the hole wherein the packer plug includes apressure reducing orifice after flowing the liquid; and providing apressure into the hell hole through the pressure reducing orifice thusfurther fracturing the subterranean location.
 12. The method of claim 9further comprising disinfecting the hole with a steam generated from theexplosion.
 13. The method of claim 9 wherein the liquid does not fill aportion of the hole extending into the subterranean location.
 14. Themethod of claim 9 further comprising forming the aerosol with acombustible fuel and an air that is ambient surrounding the surface ofthe earth proximate the hole.
 15. The method of claim 9 furthercomprising mixing a proppant with the liquid at least one of prior andduring the flowing of the liquid into the hole.
 16. The method of claim15 further comprising flowing the liquid into the subterranean locationfollowing the explosion.
 17. The method of claim 16 further comprisinginserting the proppant into a plurality of fractures formed in the shaleformation following the explosion.
 18. The method of claim 9 furthercomprising flowing the liquid into the hole following the auto-ignitionand providing additional fracturing by creating a steam and a thermalshock to the subterranean location.
 19. The method of claim 9 whereinthe liquid includes a mixture of liquid water and a gel made from atleast one of guar and cross linked polymers.
 20. The method of claim 16wherein the subterranean location includes at least one of shaleformations, tight formations, porous formations, vertical wells, andhorizontal wells.